Is there any paper or balloon simulation?
A very simple way is to set the scene gravity to a positive value (by default is the usual -9.81), and set a simulation for you baloon...



then (eg) a rigid body, but also cloth works (you just inverted the "falling" direction, and/or acceleration):



then, starting the animation with ALTA your ballon will fly upwards...



You could also add an empty with wind effect, if strong enough will move your uplifting baloon along the wind direction...